All three sound as if they've got a wonderful home with you. It always come through in the post when a person knows their animals as well as you do, that they also love them dearly and want the best for them. They are all very lucky to have come into your care I think.
It's very normal for BP's to be a bit skittish especially as youngsters. Instincts tell them that they are just as much a prey item as a predator at that age so they tend to be very careful and can be defensive and a bit nippy or striking at you. It's just nature's way to try and help them survive their early years I think. Most of them will eventually calm down as they mature and get used to simple habits and routines. Most of ours are a bit head shy when it comes to things coming down from above them but will allow a nice under the "chin" rub. Again that's just about instinct. A predator would stike down at their heads so they like to protect themselves by avoiding that movement and by their classic balling up behaviour.